Liu Xiaojun, Lang Jidong, Li Shijun, Wang Yuehua, Peng Lihong, Wang Weitao, Han Yingmin, Qi Cuixiao, Song Lei, Yang Shuangshuang, Zhang Kaixin, Zang Guoliang, Pei Hong, Lu Qingqing, Peng Yonggang, Xi Shuxue, Wang Weiwei, Yuan Dawei, Bing Pingping, Zhou Liqian, Tian Geng
School of Computer Science, Hunan University of Technology, Zhuzhou, China.
Bioinformatics Department, Geneis (Beijing) Co. Ltd., Beijing, China.
Front Genet. 2020 Feb 28;11:147. doi: 10.3389/fgene.2020.00147. eCollection 2020.
Human blood contains cell-free DNA (cfDNA), with circulating tumor-derived DNAs (ctDNAs) widely used in cancer diagnosis and treatment. However, it is still difficult to efficiently and accurately identify and distinguish specific ctDNAs from normal cfDNA in cancer patient blood samples. In this study, ctDNA fragment length distribution analysis showed that ctDNA fragments are frequently shorter than the normal cfDNAs, which is consistent with previous findings. Interestingly, the ctDNA fragment length was found to be partially associated with the mutant allele frequency, with a low mutant allele frequency (< ~0.6%) associated with a longer ctDNA fragment length when compared to normal cfDNAs. The findings of this study contribute to improving the detection of low-frequency tumor mutations.
人类血液中含有游离DNA（cfDNA），循环肿瘤来源的DNA（ctDNA）在癌症诊断和治疗中被广泛应用。然而，在癌症患者血液样本中，仍然难以高效、准确地从正常cfDNA中识别和区分特定的ctDNA。在本研究中，ctDNA片段长度分布分析表明，ctDNA片段通常比正常cfDNA短，这与先前的研究结果一致。有趣的是，发现ctDNA片段长度与突变等位基因频率部分相关，与正常cfDNA相比，低突变等位基因频率（<~0.6%）与较长的ctDNA片段长度相关。本研究结果有助于改善低频肿瘤突变的检测。
